The overall objective of the program remains: to determine the influence of hormonal and other factors on fetal lung maturation. In the past year evidence was found that the following factors have a major influence on fetal lung maturation: (a) maternal nutrition during pregnancy (b) fetal infections and episodes of stress (c) sex of the fetus (d) fetal decapitation (e) fetal corticosteroids (f) thyroid hormones. In the next year major emphasis will be placed on developing experimental models to explore the nutritional findings generated to date. Attempts will be made to determine the interactions (if any) between nutritional and hormonal regulation of fetal lung maturation.